This invention relates to a steering device, in which a clutch of a remote control vehicle toy, such as a radio-controlled vehicle toy, is improved.
Heretofore, there is known a steering device of an automotive vehicle toy of the type mentioned above as discussed in an early laid-open publication of a Japanese Utility Model Application No. 55269/1988. This steering device has an operating mechanism comprising a chassis for supporting at front end portion thereof a pair of steering wheels such that the steering wheels can make a change of direction, a pair of tie rods connected at one ends thereof to the pair of steering wheels, respectively, and an operating member horizontally pivotably supported on the chassis and connected to the other ends of the tie rods. The steering member is connected, through both a clutch and a mechanical reduction gear, to a small-sized steering electric motor which is also mounted on the chassis. The steering member is biased by a return spring into a neutral position.
As for the clutch, a holding disc is firmly secured to a rotary shaft of the small-sized steering electric motor, a plurality of arcuate clutch elements are engaged with the outer periphery of the holding disc, and an outer cylindrical member, the inner peripheral surface of which is pressure contacted by the clutch elements, is firmly secured to a gear on the driving side in the mechanical reduction gear.
The conventional steering device thus constructed is operated as follows. That is, for example, a hand-carry type transmitter is operated to transmit instructions to a receiver contained in the automotive vehicle toy in order to drive a small-sized driving electric motor by utilizing dry batteries loaded in the vehicle toy as a power source. In accordance with the instructions from the transmitter, the driving electric motor causes the automotive vehicle toy to run forwardly and backwardly. The small-sized steering electric motor is also rotated normally and reversely in accordance with the instructions from the transmitter. Upon rotation of the small-sized steering electric motor, a driving force thereof is transmitted to the steering member in the steering mechanism through the clutch and mechanical reduction gear in order to cause the steering member to be pivoted against the return spring, so that the steering wheels would be pivoted through the tie rods, etc., thereby making a change of direction rightwardly and leftwardly. When the transmitter is brought back to the neutral position, the supply of an electric current to the small-sized steering electric motor is cut, so that the clutch would be turned off. In this condition, the steering member is brought back to the neutral position by the return spring. As a result, the steering wheels are brought into a straight-forward condition.
During the driving of the small-sized operating electric motor, the clutch elements are moved towards the outer periphery side of the holding disc by a centrifugal force caused by rotation of the rotary shaft, so that the clutch elements would be brought into pressure contact with the inner peripheral surface of the outer cylindrical member. As a result, the clutch is turned on. On the contrary, when the supply of the electric current to the small-sized operating electric motor is cut, the pressure contacting relation between the clutch elements and the inner peripheral surface of the outer cylindrical element is removed. As a result, the clutch is turned off. In this condition, the steering wheels are brought back to the neutral position by the spring force of the return spring.
However, the above-mentioned steering device for an automotive vehicle toy has the following problems. When the spring force of the return spring and output of the small-sized operating electric motor are changed by some reasons (for example, change in size of the steering wheels), the clutch is also required to be replaced by another one having a different size. This means that the clutch must also be changed in accordance with various kinds of automotive vehicle toys. Therefore, production efficiency is bad.
The above prior art device has additional problems in that when the clutch is repeatedly turned on and turned off, the temperature within the outer cylindrical member becomes high because of heat caused by friction between the outer peripheral portions of the clutch elements and the inner peripheral surface of the outer cylindrical member. Therefore, the outer cylindrical member and clutch elements must be formed of a heat-proof material so that they can stand a high temperature.